Kelly Dilliard: Plankton Nets and a Right Whale Calf, June 2, 2015

NOAA Teacher at Sea
Kelly Dilliard
Onboard NOAA Ship Gordon Gunter

May 15 – June 5, 2015

Mission: Right Whale Survey
Geographical area of cruise: Northeast Atlantic Ocean
Date: June 2, 2015

Weather Data from the Bridge:

Air Pressure: 1017.02 mb
Air Temperature: 12.5 degrees C
Relative Humidity: 96%
Wind Speed: 7 knots
Wind Direction: 355 degrees

Science and Technology Log:

Sarah Fortune

Sarah Fortune with a full cod end.

Sarah Fortune, a graduate student at the University of British Columbia (UBC) was testing her plankton net a few days ago and I thought that it would be fun to describe the process.  A plankton net is hoisted overboard on a similar winch and winch cable as the CTD and is used to collect samples of plankton from the ocean.  A single plankton net has a large hoop at the opening, about 50 cm in diameter that then tapers down to a collection container, called a cod end, at the other end.  The plankton net is a little over 3 meters long.  Many plankton nets are actually paired side by side and commonly referred to as “bongo” nets for due to the two hoops looking like bongo drums.  The mesh of the net is made of nylon and can vary in mesh size.  This particular net has a mesh of 330 microns or a third of a millimeter.  This allows researchers to capture very small plankton (millimeter sized).

Plankton net fully extended after being down at about a depth of 150 meters.

Plankton net fully extended after being down at about a depth of 150 meters.

trip mechanism

Trip mechanism used to open and close the plankton net.

The plankton net that Sarah will be using for her research on bowhead whales is designed to open and close at specific depths using a special clasp, called a double trip mechanism.  A rolled up net is lowered to the target depth, a weight is sent down the winch cable and opens the double trip mechansim and the net.  As the boat moves, ever so slightly, organisms are collected in the net.  The net is then brought back to the surface using the winch and then closed again with a weight at another target depth.  I gathered that the double trip mechanism was a bit finicky, so Sarah was practicing the technique.

Plankton net

Washing down the plankton net.

Once the net was out of the water, it was washed down with a hose to make sure that all of the organisms were in the cod end.  Further washing occurred on deck.  The cod end also contains mesh in spots, so the excess water flushes out and the organisms are left in the container (the cod end).  If there is a lot of excess water and organisms these are dumped into a bucket and then brought up to the wet lab to be processed.  A subset of the sample was poured into a test tube, via a funnel, and put in a freezer for further examination off the ship.  If there is excess water, the sample is poured through a mesh sieve to remove the excess water.  Other samples were also saved in beakers.

cod end

Cod end with lots of Calinus finmarchicus.

Sieve

Collection being sieved. The red coloring of the sample comes from Calinus finmarchicus.  There are also some clear jellyfish in there, but they are difficult to see.

Sarah also had a stereoscopic microscope along to examine the catch, though this is a somewhat difficult task as the specimens move around a lot with the ship’s motion.  The target specimen was Calanus finmarchicus, the primary food of the North Atlantic Right Whale.  These are incredibly tiny organisms, typically ranging in size from 2-4 millimeters.  At one point Dr. Baumgartner had one on his finger and even that was difficult to see except for the red pigment.  He also related to us onlookers an interesting analogy of how much an individual right whale would need to consume in one day.  Basically, every right whale needs to eat the weight of a Volkswagen Beetle of Calanus finmarchicus every day.  That is a lot of very small organisms.  Some other interesting organisms that were captured in the plankton net over the day included microscopic starfish, jellyfish, krill, and a fish (which was thrown back into the ocean).

Sample

View of sample using the light of the microscope.  The red organisms with out black eyes are Calinus finmarchicus.  The organisms with two black eyes are krill.

Personal Log:

In past few days we have encountered patches of thick fog that in some cases have lasted for hours.  This has hampered our whale observations, one because we cannot see them in the fog, and two we cannot stand up on the fly bridge (above the bridge) when the fog horn is on (very loud).  So, our sighting numbers are significantly down, with a whole day in which we did not see a single whale of any kind.  One evening, though, we had a really good show from a mother and calf North Atlantic right whale.  We have seen these two before on two occasions.  The mother is 1950.  Her calf was up near the surface for nearly an hour shaking its fluke and flippers, breaching, and rolling onto its back.  The calf also rolled all over the mom when she was at the surface.  This all occurred very close to the ship so everyone on the fly bridge and the bridge was able to watch and see the action pretty clearly.  I was able to capture several photographs and tried a few videos with my camera.  It is not very easy to shoot videos on a boat that is rocking up and down, but I think they turned out okay.

Right whale calf

Various images of right whale calf: “V” shaped blow, characteristics of right whales (upper left), fluke (upper right), calf swimming on its back with flippers flapping (middle row), and a head shot (bottom row). Images collected under MMPA research permit #17355. These photos are cropped images of photographs taken with a telephoto lens.

Breaching right whale

Right whale calf breaching. Images collected under MMPA research permit #17355. These photos are cropped images of photographs taken with a telephoto lens.

Right whale

Right whale calf rolling over the back of its mom, 1950. Notice the callosities pattern on the mom and the two blow holes. Images collected under MMPA research permit #17355. These photos are cropped images of photographs taken with a telephoto lens.

Only a few more days on the ship.  Unfortunately with the fog and the lack of right whale sightings the scientists have not necessarily accomplished all of their objectives, including testing out a new tag that could be used to track a whale for several days.  We come into port early Friday, June 5th.

Group shot

Group shot of the scientists on board (minus Eric Matzen who was only on for the first leg).  Back row from left to right: Mark Baumgartner, Lisa (Grace) Conger, Corey Accardo, Sarah Fortune, and Hansen Johnson.  Front row from left to right: Kelly Dilliard (me), Sabena Siddiqui, Jenn Gatzke, Suzanne Yin, Peter Duley (chief scientist), Divya Panicker, and Chris Tremblay.

Whale poop (strangely colored area) from a fin whale.   Images collected under MMPA research permit #17355. These photos are cropped images of photographs taken with a telephoto lens.

Whale poop (strangely colored area) from a fin whale. Images collected under MMPA research permit #17355. These photos are cropped images of photographs taken with a telephoto lens.

Kainoa Higgins: Mantas and Megalopae, June 28, 2014

NOAA Teacher at Sea
Kainoa Higgins
Aboard R/V Ocean Starr
June 18 – July 3, 2014

Mission: Juvenile Rockfish Survey
Geographical Area of Cruise: Northern California Current
Date: Saturday, June 28, 2014

Weather Data from the Bridge: Current Latitude: 45° 59.5’ N Current Longitude: 125° 02.1’ W Air Temperature:  12.7° Celsius Wind Speed: 15 knots Wind Direction: WSW Surface Water Temperature: 15.5 Celsius Weather conditions: Partly cloudy

Find our location in real time HERE!

Science and Technology Log:

Neuston Net and Manta Tow Today, the weather is pleasant but the sea seems more than restless. The show must go on! I step onto the open deck behind the wet lab just as Dr. Curtis Roegner, a fisheries biologist with NOAA, is placing a GoPro onto the end of an extensive net system.

Dungeness Crab – A Pacific Northwest Delight Photo Credit: http://www.smokeybay.com

While Curtis specializes in the biological aspects of oceanography, he is especially interested in the synthesis of the ocean system and how bio aspects relate to other physical and chemical parameters. He joins this cruise on the Ocean Starr as he continues a long-term study of distribution patterns of larval crabs. The species of focus: Cancer magister, the Dungeness crab; a table favorite throughout the Pacific Northwest.

While I have been known to eat my weight in “Dungies”, I realize that I know very little about their complex life cycle. We begin with “baby crabs”, or crab larvae. Once they hatch from their eggs, they quickly join the planktonic community and spend much of their 3-4 month developmental process adrift – at the mercy of the environmental forces that dictate the movement of the water and therefore, govern the journey of these young crustaceans. It has been generally assumed that all planktonic participants float wherever the waters take them. In that context, it makes sense that we have been finding large numbers of larvae miles offshore during our nighttime trawl sorting. Still, not all are swept out to sea. Every year millions make their way back into the shallows as they take their more familiar, benthic form which eventually grows large enough to find its way to a supermarket near you. The question is: How? How do these tiny critters avoid being carried beyond the point of no return? Is it luck? Or is there something in the evolutionary history of the Dungeness crab that has allowed it to adapt to such trying conditions?

Dungeness Crab Megalopae

“Dungie” babies

Curtis tells me about recent research that suggests that seeming “passive” plankton may actually have a lot more control of their fate than previously supposed.  By maneuvering vertically throughout the column they can quite dynamically affect their dispersal.  Behavioral adaptation may trigger vertical migration events that keep them within a particular region, playing the varied movement of the water to their advantage.  Curtis believes the answer to what determines Dungie abundance lies with with the Megalops, the final stage of the larva just prior to true “crab-hood”. By the end of this stage they will have made their way out of the planktonic community and into estuaries of the near shore zone.

Kainoa and Curtis

Dr. Curtis Roegner explains the importance of his study

This continued study is important in predictably marking the success or failure of a year’s class of crab recruitment. That is to say, the more Megalopae that return to a region, the better the promise of a strong catches for the crabbing industry – and a better chance for you and me to harvest a crab or two for our own table!

As Curtis and I discuss his research, he continues preparing his sampling equipment. The instrument looks similar to the plankton nets we use in marine science at SAMI only it’s about ten times longer and its “mouth” is entirely rectangular, unlike the circular nets I am used to using. I’ve heard the terms “manta”, “bongo” and “neuston” being tossed around lab and yet I am unable to discern one from the other. It’s time I got some answers!

Curtis explains that the Megalopae he wants to catch are members of the neuston, the collective term given to the community of organisms that inhabit the most surface layer of the water column. The Neuston net is named simply for its target. It occurs to me that a “plankton net” is a very general term and that they can come in all shapes and sizes. In addition, the mesh of the net can vary drastically in size; the mesh on our nets at school is roughly 80µm, while the mesh of this net is upwards of 300μm (1 µm or micrometre is equivalent to one millionth of a metre).

Manta tow & Neuston net

The manta body design for neuston sampling. A specialized plankton tow.

I’m still confused because I am fairly certain I have heard others refer to the tool by another name. Curtis explains that while any net intended to sample the surface layer of the water column may be referred to as a neuston net, this particular net had a modified body design which deserved a name of its own. The “manta” is a twin winged continuous flow surface tow used to sample the neuston while minimizing the wake disturbance associated with other models. The net does seem to eerily resemble the gaping mouth of a manta ray. These enormous rays glide effortlessly through the water filtering massive volumes of water and ingesting anything substantial found within. On calm days, our metallic imposter mimics such gracefulness. Today however, it rides awkwardly in the chop, jaggedly slicing and funneling the surface layer into its gut. It’s all starting to make sense. Not only is this a plankton net designed to sample plankton, it is also a plankton net designed to sample only the neuston layer of the planktonic community.   The modified body sitting on buoyed wings designed to cover a wider yet shallower layer at the top of the water column further specified the instrument; a neuston net towed via manta body design for optimized sampling. Got it.

Collected Plankton Sample

A filtered sample of various crustaceans collected from the neuston

After the tow is complete, Curtis dumps the cod end of the net into a sieve, showing me an array of critters including more than a dozen Megalopae! Two samples are frozen to ensure analysis back at the Hammond Lab in Astoria. There, Curtis will examine the developmental progress of the Megalopae in relation to the suite of data provided by the CTD at each testing site. This information, along with various other chemical and physical data will be cross-examined in hopes of finding correlation – and perhaps even causation – that make sense of the Dungeness crabs’ biological and developmental process.

Analysing CTD Data

Dr. Curtis Roegner looks for patterns relating crab Megalopae and CTD data

The CTD 

CTD

The CTD measures conductivity, temperature and depth among other auxiliary measurements

Fundamentally, a CTD is an oceanographic instrument intended to provide data on the conductivity, temperature and depth of a given body of water. The CTD is one of the most common and essential tools on board a research ship. Whether it’s Jason exploring benthic communities, Sam hunting jellies, or Curtis collecting crab larvae, all can benefit from the information the CTD kit and its ensemble of auxiliary components can provide about the quality of the water at a given test site. In general, the more information we collect with the CTD the better our ability to map various chemical and physical parameters throughout the ocean. Check out the TAScast below as I give a basic overview of and take a dive with the CTD and its accessories.  

 

 

Personal Log:

Just when I thought I was beginning to get the hang of it…. Hold on, I have to lie down. As I mentioned above, the seas have been a bit rougher and I’ve been going through a phase of not-feeling-so-hot for the first time this trip. It’s odd because we hit some rougher ocean right out of Eureka and it didn’t seem to faze me much. I stopped taking my motion sickness medicine a few days in, and though I’ve picked it back up just in case, I’m not entirely convinced it’s the only contributing factor. I think it has more to do with my transition onto the night shift and all the plankton sorting which requires lots of focus on tiny animals. The night before last was particularly challenging. In the lab, all of the papers, books and anything else not anchored down slid back and forth and my body felt as if it were on a giant swing set and seesaw all at once. In addition, each time I looked out the back door all I could see was water sloshing onto the deck through the very drainage holes through which it was intended to escape. I remember wondering why there were so many rolls of duct tape strapped to the table and why chairs were left on their side when not in use. Well, now I know. Earlier today we made a quick pit stop in Newport, Oregon – home of the Hatfield Marine Science Center as well as NOAA’s Marine Operations Center of the Pacific. In short, this is where NOAA’s Pacific fleet of vessels is housed and the home base to several members of my science team, including Chief Scientist, Ric Brodeur.

The NOAA Pacific Fleet

The NOAA Pacific fleet at rest in Newport, OR.

I remember the anticipation of seeing the R/V Ocean Starr, a former NOAA vessel, for the first time. Growing up in Hawai’i, I remember these enormous ships making cameo appearances offshore, complete with a satellite dome over the bridge, only imagining the importance of the work done aboard. Now here I was, walking amongst the giants I idolized as a kid – the difference being that my view was up close and personal from behind the guard gate, a member of their team. I’m totally psyched even though I attempt to pretend like I’ve been there before. As much as I could have spent all afternoon admiring, I needed to make the most of our two hour layover in the library uploading blog material. Unfortunately the satellite-based internet is incredibly finicky out at sea. It’s a first world problem and understandably a part of life at sea, I realize, but all the same, I apologize to all those anticipating regular updates. I continue to do the best I can. I can say, however, that the Hatfield Marine Science Center boasts a fantastic library. I look forward to exploring the rest of the facility upon my final return in a little over a week. ‘Till then, BACK TO SEA!

Christina Peters: Finding Plankton on Oregon II, July 13, 2013

NOAA Teacher at Sea
Chris Peters
Onboard NOAA Ship Oregon II
July 10 – 19, 2013

Mission: SEAMAP Summer Groundfish Survey
Geographic Area of Cruise: Gulf of Mexico, leaving from Pascagoula, MS
Date: July 13, 2013 

Weather and Location:
Time: 23:24 Greenwich Mean Time (7:24 p.m. in Rockville, MD)
Latitude:  25.5340
Longitude:  -82.0215
Speed (knots):  9.30
Water temperature:  28.90 degrees Celsius
Salinity (PSU = Practical Salinity Units): 35.38
Air temperature:  31.20 degrees Celsius
Relative Humidity:  65%
Wind Speed (knots):  8.92
Barometric Pressure (mb): 1013.34
Depth (m) = 19.20

Science and Technology Log

Our Mission

In my introduction I explained that SEAMAP is a state, federal, and university program.  In fact, there is a managing unit called the SEAMAP– Gulf Subcommittee of the Gulf States Marine Fisheries Commission’s Technical Coordinating Committee who manages the activities and operations, including collecting samples and interpreting data, of the Gulf participants, including the Mississippi Laboratory of NOAA and the states of Louisiana, Mississippi,Texas, Alabama, and Florida, as well as certain universities.  Parts of the program include bottom trawls, CTD deployment, and Bongo and Neuston tows.  The bottom trawls involve towing nets at randomly selected spots for ten to thirty minutes. The sea life caught in the nets, normally shrimp and other animals that live at the bottom of the Gulf, are sorted, identified and measured.  All of the data is recorded and helps to determine where the fish and shrimp are, and how much exists in the Gulf.  Because the NOAA Laboratory and the states have worked so well together on this project, most of the trawls were completed on earlier legs of the trip and on the state boats.  We have had opportunities, though, to observe and identify some of the fish from an earlier leg that had been put on ice.  We’ll come back to that process a bit later.

The first twenty-four hours underway were spent heading to our first station, off the southwest coast of Florida.  We have spent much of our time on this leg of the trip completing plankton collections.  My students should remember that plankton includes small and microscopic (too small to see with only your eyes) organisms. The organisms may be animals, plants and plant-like organisms, or bacteria.  The plankton found in the water can tell what the animal population looks like, or will look like if the conditions of the water do not change too much.  Plankton is also a source of food for certain animals, so looking at plankton can give us information about whether enough of a food source is present for those animals.  The purpose of the Bongo and Neuston tows is to collect plankton.  Before we do those tows at each station, however, we deploy the CTD to collect some important information.

Bringing in the CTD

A scientist and deckhand help bring in the CTD

Taking water samples from the CTD

The chief scientist, Kim Johnson, takes water samples from the CTD to verify it’s dissolved oxygen readings.

CTD stands for Conductivity, Temperature, and Depth.  The machine collects data in those areas, as well as other data.  The conductivity data tells how much salt (salinity) is in the water because the amount of salt affects how well the water will conduct (allow to pass through) electricity.  The CTD also measures the oxygen content of the water.  Remember learning about algae bloom in the Chesapeake Bay, and how the algae sucks up all of the oxygen, leaving the plants and animals in the area to die?  When a body of water has an unhealthy level of oxygen, it is called hypoxic.  Scientists are worried about the same kind of thing happening in the Gulf of Mexico, so determining the oxygen content in the water provides important information.  In the stations we have tested so far, the oxygen content has been healthy.  However, we have been far from land and much closer to where the Atlantic Ocean meets the Gulf.  To learn more about hypoxia in the Gulf of Mexico, visit NOAA’s hypoxia page.  Don’t forget to click on the links at the bottom that will take you to descriptions of the problems and causes of hypoxia in the Gulf.

After bringing the CTD back onto the deck, it is time to start a Neuston tow.  The Neuston net is very fine, and attaches to a one meter by two meter frame at the top.  The net gets narrower, and attaches to a “cod end”, a plastic cylinder with screened openings, at the bottom.  This is hoisted out of the boat and into the water by a crane.  It takes several people to launch the Neuston, as the frame is heavy, and it can be hard to manage in the wind.

Neuston net before deployment

The Neuston net is tied down to the boat until it is ready to be deployed.

The Neuston is pulled through the water, with about a foot above the surface, and the rest below.  The purpose is to collect plankton on or near the surface of the water.  Since sargassum, or seaweed, often floats on the surface of the water, sometimes the Neuston collects a lot of that.  We continue to tow the net for ten minutes, and then retrieve it into the boat, again using the crane.  While we did not do trawls and pull in large fish, we did see different kinds of baby fish at almost every station.

Neuston net

The Neuston net is dragged at the top of the water for five to ten minutes

The Bongo contains two 61 centimeter, circular, sturdy plastic frames, to which fine nets are attached.  These nets also narrow to a small area, to which cod ends are attached.  The Bongos are lowered off the port side by using the J frame. The bongos are towed from the surface to the bottom, but no deeper than 200 meters.  The bongo also has the flowmeters on it to calculate how much water passes through the net. The sample is used to estimate the populations, number, and location of animals in parts of the Gulf.  The Bongo also has instruments attached to it that measure temperature, salinity (salt), and depth.  In addition, the bongos have flowmeters attached to calculate how much water passes through the nets.

Bongo nets

The Bongo nets must be rinsed down before being brought into to boat to make sure no plankton is stuck at the top of the nets.

These are complicated tools, and some of the instruments are electronic.  If the instruments are not working correctly, the scientists and engineers must have a back-up plan.  In fact, at one station, the Bongo instruments were not giving accurate readings when the head of the watch (the scientist in charge) looked at the readings from inside.  The back-up plan was for the deckhands to use less accurate depth finding instruments when lowering the Bongo.  This can sometimes present a problem because if the instruments are off, and the Bongo drags on the bottom, a lot of mud can end up in the sample.  Fortunately, a little troubleshooting, in the form of tightening some connections, solved the problem.  Sometimes it’s easy to forget to check the obvious!

Once the Neuston and Bongo are up, we can detach the cod ends, and get to work preserving the plankton samples.  The plankton from the Neuston, and from each of the Bongo cod ends, are preserved and stored separately.  The Neuston and right Bongo plankton are rinsed through a very fine sieve with a chemical solution that is mostly ethanol, and then poured through a funnel into a jar, which is finally filled with the ethanol solution.  The left Bongo plankton is handled similarly, but instead of being stored in ethanol, it is stored in salt water from the Gulf, and a small amount of formalin.  Formalin contains a small amount of formaldehyde, and is used to preserve tissues.  It is a toxic chemical that is harmful to humans, and must be handled very carefully, always using gloves.  The samples are later sent to various laboratories to be sorted and counted.  In addition to providing information about amount and location of different species, scientists can also use the preserved plankton to determine the age, as specific as the number of days old, and genetics of the baby sea animal. The formalin helps preserve the otoliths a LOT better, where the ethanol helps preserve the tissue and/or DNA better.  The otolith is part of the inner ear of the animal and is the part that is used to determine age.

Work station at the stern of the boat

The work station at the stern of Oregon II is where we rinse the plankton and add the chemicals for preservation.

Rinsing the plankton

Sometimes we have to remove jellyfish from our samples. The plankton must be rinsed off the jellyfish before counting and discarding them.

With stations normally being about three hours apart, it would seem like we should have a lot of down time.  However, when there is a lot of sargassum in the Neuston, it must be rinsed to try to get the plankton out of it.  This can take quite a long time.  In addition, sometimes we do get small fish or other animals that need to be sorted, counted, measured and weighed.

Sargassum

There were over 300 of these file fish in one plankton sample. The color made them difficult to find in the sargassum.

A pipe fish from one of the Neuston samples.  What does it remind you of?

A pipe fish from one of the Neuston samples. What does it remind you of?

Plankton sample

This is a plankton sample from a Neuston tow after it has been preserved in ethanol.

Don’t forget to track our progress by visiting http://shiptracker.noaa.gov/shiptracker.html and choosing Oregon II.  While you are there, don’t forget to check out the different types of maps available for tracking Oregon II.  Look in the upper left-hand corner (Streets, Topo, Imagery, NOAA Nautical Charts, and Weather).

Personal Log

Settling in and enjoying the ride

The first three days of the trip had us motoring through incredibly calm waters and sunny days.  Some of the veteran crew members commented that they had never seen the Gulf so calm.  As we traveled further from Pascagoula, the water started getting bluer and bluer.  It is hard to describe the deep blue that we sailed through and the camera just doesn’t seem to capture it.  As we left the waters around Pascagoula, we saw many large ships, possible oil tankers, and quite a few oil rigs.  However, once we passed them, we’ve barely seen another boat.  It is something to look out from the bow of the boat and see nothing but water in every direction.

A calm day in the Gulf of Mexico

A calm day in the Gulf of Mexico

As promised, the food on board is delicious. The cooks take great pride in the food they serve, and there are always choices at every meal.  We’ve had beef tenderloin, veal parmesan, omelets, fresh fruit, fresh vegetables, pasta, Mexican, chocolate custard pie, cookies, pecan pie – all homemade!  The galley is also well-stocked with snacks.  Meals are served on a strict schedule – about an hour and a half for each meal.  However, if you know you will miss a meal, the cooks are happy to set some food aside for you, nicely wrapped in the refrigerator.  Luckily for me, I have the day shift, and if I miss a meal, it is normally breakfast.

Everyone on the ship has been very encouraging and helpful.  Some of the guys did a dive and brought me back some interesting shells to share with my students.  The other scientists have been incredibly patient and helpful.  Kim, the chief scientist, is a great teacher and is always looking for opportunities for me to learn something new, or practice something I just learned!

Did you know?

The starboard side of the ship is the right side, and the port side is the left side.  Starboard comes from the old Anglo-Saxon word, “steorbord” because the steering oar was on the right side of the boat.  Because of this, the ship would pull up to the dock, or port, on the left side. This would avoid damaging the steering oar.

Questions for my students:

What unit of measurement do you think we use to measure the small fish found in the Neuston and Bongo tows?

Can you think of any sea animals that use plankton as their main source of food?  It is okay to research this before you answer!

Thank you for visiting my blog.  I hope you will check back in a few days for an update!

Thomas Ward, September 13, 2010

NOAA Teacher At Sea: Thomas Ward
Aboard NOAA Ship Miller Freeman

Mission: Fisheries Surveys
Geographical Area of Cruise: Eastern Bering Sea
Date: September 13, 2010

The Procedure

The way that we collect data is done by three methods. They are the beam trawl, the benthic sled and the benthic grab. The beam trawl is a metal beam supported by a cable on the ship. Hanging from the beam is a net that when dragged behind the ship opens up. The trawl is pulled behind the ship for a specific amount of time.

The benthic sled is a piece of equipment that looks like it would be right at home on the snowy slopes of Central New York. It is a sled that gets dragged on the bottom and collects plankton (look out Eugene). The net is a finer mesh than the one used on the beam trawl. At the end of the net is a container that collects the plankton, we call it a cod end.  At the opening of the net is a device called the flow meter which looks like a little hand held fan. This performs the function of measuring the amount of water or flow that is going through the net. The meter has a counter on it and needs to be read and reset at each sampling station. This instrument gives the scientists a sense of the volume of water flowing into the net.

Flow Meter

Benthic Sled

The last device we are using is the benthic grab.  This device and the wet bulb on the bridge are instruments closest to my curriculum, Earth Science.  In fact, while on the bridge one officer asked another for the wet bulb temperature, very cool, I almost pulled out my sling psychrometer and compared data.  Any how, the grab is opened up and set and then lowered into the water.  When the grab hits the bottom, the weight and the downward force of the grab forces it shut, and into the bottom, scooping up sediment as it closes.  Of course because of the nature of this scientific expedition we are more concerned with organic matter than sediment.  I will have to say the scientist that I am working with have a natural curiosity toward all of Earth’s wonders.

These devices are deployed one at a time.  After each piece returns to the surface the crew maneuvers the ship so that subsequent samplings are performed at the same area.

I was going to write about life on board but the seas have gotten rougher and I am sea sick.

Natalie Macke, August 28, 2010

NOAA Teacher at Sea: Natalie Macke
NOAA Ship: Oscar Dyson

Mission:  BASIS Survey
Geographical area of cruise: Bering Sea
Date: 8/28/2010
It’s Fish Feeding Time…
Weather Data from the Bridge :
Visibility :  <0.5 nautical miles  (Wondering what a nautical mile is??)
Wind Direction: From the W at 20 knots
Sea wave height: 2-3ft
Swell waves: WSW, 4ft
Sea temp:9.1 oC
Sea level pressure: 1013.0 mb
Air temp: 9.7 oC
Science and Technology Log:

Euphausiid Specimens (zooplankton)

We’re up to station #40 now and everyone certainly has their routine down.  One type of sampling I have yet to cover is the microscopic life; the base of the food web.  A look at the marine fisheries food web quickly reveals that in order to support the commercial fisheries as well as the vast number of marine mammals and ocean birds, there must be an abundance of phytoplankton and zooplankton available in the Bering Sea.  Evidence of this food chain is demonstrated by dissecting the stomach of a salmon.  The sample (in the picture below) revealed that the salmon had recently dined on euphaussids (commonly known as krill).   Before getting into how the zooplankton samples are collected, first let me go back and touch on the base of the food web; phytoplankton.  These samples are collected from the Niskin bottles on the CTD each cast.  The samples are preserved with formalin and will be brought back to the lab for further analysis.  Now, back to the critters..

Dissecting a salmon stomach

At every sampling station on the side deck and immediately after each CTD cast, zooplankton net tows are completed.  There are three different tows being used for the BASIS survey. The first two are vertical tows where nets that are weighted are dropped to the seafloor and then brought back to the surface thus sampling a vertical water column. The pairovet, named from the fact that is was designed as a “pair of vertical egg tows” (designed to collect pelagic egg samples) has a netting mesh size of 150 microns.  The net is simply deployed with a weight on the bottom.  When it reaches the deepest part of the water column it is brought back to the surface collecting its’ sample.  Another similar net with a 168 micron mesh size is named the Juday.  Once either of these nets is brought to the deck, it is washed down and anything caught is captured in the cod end (the name for the PVC bucket at the bottom of the net).

Cod end for Bongo

Deploying the Bongo nets off the starboard side

The last type of tow that is completed for the BASIS survey uses the Bongo nets.  This tow is considered an oblique tow since the nets essentially are lowered to about 5m from the ocean bottom and towed for a certain length of time.  If you remember from the acoustics, in daylight hours the zooplankton migrate to the ocean bottom to hide from their prey.  Since our sampling is done in daylight hours, the deep sampling depth is where we expect to find the highest density of zooplankton sample.  The mesh sizes on the two nets of the Bongo are 335 and 505 microns.  This allows for sampling of zooplankton of different sizes.   The samples are collected on board and then taken back to the lab for analysis.  They are separated by species, counted and weighed.  Biomass and species composition is determined for each sample.  The majority of the zooplankton we have seen this cruise have been euphaussids and copepods of varying types.

Oh where, oh where does the Internet go??

So as August winds down and the school year gears up, my connection to the Internet is becoming more and more important.  Since my Oceanography class is with the Virtual High School, I have to essentially set up my virtual classroom in these upcoming days.  I’ll assume my esteemed colleagues will assist me in unpacking lab equipment back at home at my physical classroom. (Even though I know.. all my orders will mysteriously wind up in other labs, I’m assured they’ll be safely placed away.)

So I tracked down Vince Welton, our Electronic’s Technician for some help understanding why sometimes I can surf, and why sometimes I can’t….

Simple…

Our Internet connection is via the geostationary satellite GE 23 at 172 degrees East. This satellite transmits over most of the Pacific Ocean (see a coverage map).  Since this satellite is positioned on the equator, that means our receiver must look essentially due south for a signal.  When our ship is northbound, the mast and stack of the Oscar Dyson simply gets in the way.  Therefore… no Internet on northbound travels.

The Oscar Dyson also has access to two Iridium satellites for communication as well as the GE 23.   These are the SAT-B which can transmit both data and voice communications and the VSAT which only allows voice transmission.  The ship can access this set of orbiting satellites when the GE 23 is unavailable due to course of travel or weather conditions.

  Personal Log
Jeanette videotaping

Jeanette videotaping

Yesterday, I got permission to stay on the trawl deck during one of our station trawls.  It was fun to be outside down with the net.  Jeanette helped do some taping which I hope to(during a few Internet-less days ahead) compile to a video for my classes.  Of course as fate would have it, our catch for the day (shown below) was not one for the record books or even worth remembering at all..  I guess that’s what the editing process is for hmmm…

Today’s catch

In the Oceanography lab, we have started our primary productivity experiments and chlorophyll analysis so learning these new procedures has been interesting and given me lots of ideas for some research topics for Edelberg’s class.  All in all, I am enjoying watching, learning and doing science here in eastern Bering Sea.  One week left..

Story Miller, July 23, 2010

NOAA Teacher at Sea: Story Miller
NOAA Ship: Oscar Dyson

Mission: Summer Pollock III
Geographical Area: Bering Sea
Date: July 23, 2010
 
Time: 1240 AKST
Latitude: 60°30N
Longitude:176°29W
Wind: 8 knots (approx. 9.21 mph)
Direction: 156° (SE)
Sea Temperature: 8.9°C (approx. 48°F)
Air Temperature: 9.2°C (approx. 48.6°F)
Barometric Pressure (mb): 1008
Wave Height: 0.5 feet
Wave Swell: 5 – 6 feet
Scientific Log:

Survey Tech Robert Spina and Fisherman Mike Tortorella deploying the CTD

We started the morning by dropping a CTD (Conductivity, Temperature, Depth) and monitoring the salinity of the ocean, the temperature, and depth. Salinity, the amount of salt in the ocean, is important as the higher the salinity the more conductivity it possesses. Conductivity is necessary for many things such as scientific observation and for marine life. For example, the transducer we use to send pings of energy through the ocean relies on conductivity and sound tends to travel better through waters with a higher salinity. Sound traveling through water is also important for animal communication. Salinity can influence the presence of fish species due to the different ways they process the water (think about freshwater fish versus saltwater fish). Water temperature is important for observing climate change. Because salinity affects the density of water (My students: remember the lab where we floated the egg with salt), it can change the temperature at which the ocean freezes. A simple example is that plain distilled water freezes at 0°C but the ocean at the surface typically begins to freeze at -1.1°C. As the water depth increases, so does the salinity and therefore as the temperature decreases the ocean does not freeze. We also launched an expendable bathythermograph (XBT) which measures depth and temperature at a deeper level than the CTD. These two tests are used to characterize the Bering Sea shelf environment.

Streaming the AWT net

Pollock caught in the codend

Approximately six hours later we spotted our first school of pollock. We shot the AWT and caught a lot of two year-old pollock and a few one year-olds! The water temperature where they were located was about 2.5°C. I quickly donned my foul-weather gear and ExtraTuffs (rubber boots) and was ready to sort fish. From one sample, we sorted the fish, separating the small one year-olds from the two year-olds. Second, we cut open the fish to locate ovaries or testes. The males and the females were separated into bins and we fondly refer to the males as “Blokes” and the females as “Sheilas.” We measured their length and entered the data into the computer. With another sample, we sexed the fish, measured their length, extracted stomach samples to see what they are eating and to collect plankton samples, and last we extracted the otoliths. Otoliths are ear-bones and they are used to measure age, very much like looking at tree rings to find the age of a tree.

Me sorting the 1 year from the 2 year-olds

The walleye pollock observation has been conducted each summer since 1979 by the Midwater Assessment and Conservation Engineering (MACE) as a program of the Alaska Fisheries Science Center (AFSC) to estimate pollock abundance and distribution. The Oscar Dyson is following a route consisting of evenly spaced (20 nautical miles) parallel transects to estimate the pollock population over the entire Bering Sea shelf. So if you are tracking the ship using “Ship Tracker” this is why we are sailing in a strange pattern!

Personal Log:

Yesterday I was slightly anxious because I chose to experiment with my sea tolerance and not take the seasickness medication. Of course the seas decided to be a little more active as we began our pollock transit. Combined waves reached 10-12 feet and I just ate plain rice and bread for supper! Today the waves are more gentle and my stomach is very excited about that! Up on the “Bridge” where the controls for driving the boat are located tends to rock with the waves the most and it was fun to try and type my blog while attempting to keep my balance! However, by the end of the day, I was well enough to help “supervise” ENS Payne in the construction of chocolate chip cookies during my time off!

Doughy thumbs up while makin’ cookies!

Dissecting the fish was incredibly fun and I cannot wait to have my students try their hands at it! I was very excited to extract otoliths because those particular bones were the fossils we used to identify the different fish species at the Always Welcome Inn in Baker City, Oregon when I was conducting research in college! To see those fossils go to the following website:

http://www.eou.edu/geology/index.html

Tomorrow we will be crossing the International Dateline and theoretically will have traveled into the tomorrow of tomorrow. The Oscar Dyson has become my time machine!

Image produced by the echo sounder telling us we have pollock! Notice how it looks different from the view in the previous blog.

Animals Viewed Today:
Least Auklet
Laysan Albatross
Fork-tailed Storm Petrels
Northern Fulmars
Short-tailed Shearwaters
Walleye Pollock

Something to Ponder:
Have you ever ordered pollock? How many of you have eaten fish sticks or surimi? Most likely you have eaten pollock and thought it was cod! Where does pollock fit in the food chain in the wild?
Also, how do you know when you have crossed the International Dateline? (Hint: check the data at the beginning of my blogs.)

Deborah Moraga, June 27, 2010

NOAA Teacher at Sea Log: Deborah Moraga
NOAA Ship: Fulmar
Date: July 20‐28, 2010

Mission: ACCESS
(Applied California Current Ecosystem Studies)
Geographical area of cruise: Cordell Bank, Gulf of the Farallones and Monterey Bay National Marine Sanctuaries
Date: June 27,2010

Weather Data from the Bridge
Start Time: 0700 (7:00 am)
End Time: 1600 (4:00 pm)
Position:
Line 10 start on western end: Latitude = 37o 20.6852 N; Longitude = 122o 56.5215 W
Line 10 end on eastern end: Latitude = 37 o 21.3466 N; Longitude = 122o 27.5634 W
Present Weather: Started with full could cover and cleared to no cloud cover by mid day
Visibility: greater than 10 nautical miles
Wind Speed: 5 knots
Wave Height: 0.5 meters
Sea Water Temp: 14.72 C
Air Temperature: Dry bulb = 14 C Barometric Pressure: 1013.2 mb

Science and Technology Log
We left Half Moon Bay at 0700 (7:00 am) to survey line 10. We traveled out to about 30 miles offshore then deployed the Tucker trawl.

Tucker Trawl

Tucker Trawl

When the team deploys the Tucker trawl the goal is to collect krill. They are relying on the echo‐sounder to determine where the krill are located in the water column. The echo‐sounder sends out sound waves that bounce off objects in the water and works much like a sophisticated fish finder. Dolphins hunt for their prey in much the same way. A computer connected to the echo‐sounder is used to display the image of the water column as the sound waves travel back to the boat. By reading the colors on the screen the team can determine the depth of krill.

Collecting krill

Collecting krill

Collecting krill

Collecting krill

Collecting krill

Collecting krill

The scientists send weights (called messengers) down a cable that is attached to the Tucker trawl as it is towed behind the boat. Once the messenger reaches the end of the line where the net is located, it triggers one of the three nets to close. Triggering the nets this way allows for the researchers to sample zooplankton at three different depths.

image of water column on computer screen

Image of water column on computer screen

When the cod‐ends of the nets were brought onboard Jaime Jahncke (scientist for PRBO Conservation Science) examined the contents. Some of the organisms that were collected were…

When the cod‐ends of the nets were brought onboard Jaime Jahncke (scientist for PRBO Conservation Science) examined the contents. Some of the organisms that were collected were.

• Thysanoessa spinifera – a species of krill

• Crab megalopa larvae
Euphausia pacifica – a species of krill